Dynamic free-form deformations for animation synthesis

摘要

Free form deformations (FFDs) are a popular tool for modeling andnkeyframe animation. The paper extends the use of FFDs to a dynamicnsetting. Our goal is to enable normally inanimate graphics objects, suchnas teapots and tables, to become animated, and learn to move about in ancharming, cartoon like manner. To achieve this goal, we implement ansystem that can transform a wide class of objects into dynamicncharacters. Our formulation is based on parameterized hierarchical FFDsnaugmented with Lagrangian dynamics, and provides an efficient way tonanimate and control the simulated characters. Objects are assigned massndistributions and elastic deformation properties, which allow them tontranslate, rotate, and deform according to internal and external forces.nIn addition, we implement an automated optimization process thatnsearches for suitable control strategies. The primary contributions ofnthe work are threefold. First, we formulate a dynamic generalization ofnconventional, geometric FFDs. The formulation employs deformation modesnwhich are tailored by the user and are expressed in terms of FFDs.nSecond, the formulation accommodates a hierarchy of dynamic FFDs thatncan be used to model local as well as global deformations. Third, thendeformation modes can be active, thereby producing locomotion